In present laboratory procedures, a laboratory which must have either limited access or totally restricted access is often encountered. One such laboratory is one wherein radioactive testing is performed. One prior art method is to cause an alarm to be sounded whenever access to the testing area is gained. Another method is to lock the area where testing is performed. Both of these prior art methods are subject to human error and may not prove reliable. An alarm which is constantly on may be annoying when an experiment is being set up and access to the area required is on a continual basis. An alarm which is turned on after an experiment is set up can be erroneously left in the off position.
In many states various types of interlock systems are required for laboratories performing tests which utilize radioactive materials. On such state in Texas which under "The Texas Regulations for Control of Radiation" Part 35 entitled "Radiation Safety Requirements for Particle Accelerators" requires six items.
The first requirement takes the general form of requiring an interlock on the door of the testing laboratory.
The second requirement, which is a further delineation of the first, requires that when the laboratory door is opened and closed, continuing operation is to be inhibited until a switch is reset on a remotely located control panel. This requirement is to prevent a person from entering the test area and remaining inside during testing.
The third requirement is for a switch which is located near the door inside the test area. When this switch is on, operation of the neutron generator (cannister) is inhibited until the switch is turned off. This requirement is to prevent a person who is accidentally locked in the test area from being subjected to neutron radiation.
The fourth requirement is to provide a flashing light at the entrance of the testing laboratory to indicate that a test is in progress and the cannister may be generating neutrons.
The fifth requirement is to provide an audible warning device to be activated fifteen seconds prior to the possible creation of neutrons.
Finally, the sixth requirement necessitates that if the power to the neutron generator is turned off at the control panel or the door interlock is interrupted then the interlock system must be rearmed before operation can resume.
These and other requirements are necessary in any doorlock system for neutron testing laboratories and are not available in prior art.